Biggest tire to fit on stock rims

Ok so basically I have stock pony's and I will not have enough money to buy rims and tires (was going to buy a 10.5'' rim with 315s, love the look) instead I will just get a nice set of sticky tires. I read a post somewhere with a yellow mustang putting M&H Racemasters Radial 305's on his stock pony's this what i would like as I want the widest tire possible. I am not worried about the reduced handling that will come with the oversized tire on the rim, just want the traction and the look, one of my co-workers is talking **** about him beating me in his little Integra, he's even got the other morons at work believing him, so we're going to go to the track and I know I'll beat him even with plastic wheels, but I want to DESTROY him for talking so much ****. So what is the biggest I can go, also what width are my rims, 8''?

Thanks

JTKZ13 how do you like those tires, how many miles have you gotten out of them so far? Thanks for the pic.

Is there any danger to going wider??? I saw a 94-94 with 305 on stock pony 16x7.5'', I already have 245 so I'm kinda looking for a bigger jump.